1. Field of the Invention
The present invention relates to a track-bound freight car comprising a box for storing bulk material, the box having a bottom portion and two longitudinally extending side walls, and comprising a longitudinally extending conveyor in the bottom portion of the box car.
2. Description of the Prior Art
U.S. Pat. No. 4,576,538, dated Mar. 18, 1986, discloses a train comprised of a series of such coupled freight cars. The bulk material may be stored and transported in the cars, and the bottom conveyors in the successive cars may be operated to convey the bulk material to adjoining delivery conveyor bands which bridge the successive cars and move the bulk material from one car to the next. Each car has its own motor for powering the conveyor drives, and a central control on a ballast rehabilitation machine controls the operation of all drives. The delivery conveyor bands project from one of the ends of the ballast rehabilitation machine and of the freight cars to reach the boxes of the adjacent cars so that the bulk material may be readily transported from the ballast rehabilitation machine to selected freight cars in the train. The successive bottom conveyors and delivery conveyor bands may be operated at high speed to transport the ballast from the ballast rehabilitation machine to the last car in the train where the bottom conveyor is driven slowly to store the ballast in the box of the last car while its delivery conveyor band stands still. As soon as the box in the last car is filled, its bottom conveyor and the preceding delivery conveyor band are stopped, and the bottom conveyor in the preceding car is slowed down for filling the box in the preceding car. This operation is repeated until all the boxes are full.
German utility model No. G 88 13 859.3, whose registration was published on Feb. 2, 1989, discloses a track-bound box car for transporting bulk material, which comprises a bottom conveyor projecting beyond a leading end of the car and ascending rearwardly. In this way, the bottom conveyor directly delivers bulk material conveyed thereby to a preceding box car. The bottom conveyor band is arranged fully within the box which is supported on the frame of the freight car.